Originally Posted by
john_tullamarine
Normally, we takeoff and maintain runway track to a suitable elevation and then turn to pick up the outbound course. If, however, a straight flight path departure is too restrictive for TOW, often we can find a curved, or turning takeoff departure, which gives a better RTOW and payload. Such turns can commence from very early in the departure, often at runway head, or at some specific position or altitude. There are various things which we take into account when designing such departures but, for the crew, the departure will be defined in the ops manual and the crew just follow what the book says for the runway. Flying a curved departure, though, is quite demanding as location and tracking is critical. As a consequence, speed and bank angle control is critical to keep the aircraft fairly close to the presumed tracking plan so that we don't get closer than intended to the obstacles of concern. At a suitable position or altitude, and once the critical obstacles have been passed, the procedure will direct the crew to turn to the departure track.
Now I understand. Its the wording and naming different for each one involved (performance engineer, regulator, manufacturer, and even differences between airlines) that made me not understand you from the beginning.
My company although not 100% correct uses the naming "Escape route" for engine out procedures after takeoff. Others use "EO route", "Emergency turn", "EO procedure" and the list goes on and on. So a curved departure would be an early turn of the "Escape route" to avoid something bigger straight ahead.
This is considered by the perf engineer on the construction of this maneuver, whereas "improved climb" ("increased V2" or "overspeed V2" as you mentioned it before) runs as an algorithm on the sofware to find a solution on that specific routing taking in account all the perf constraints.
By the way, as demanding is to fly an early turn for your EO route, its also demanding when the SID has a very early turn but your EO route goes straight or turns the other side. This applies more when you have an engine failure at low altitudes (around 300-600ft) which will make the crew to respond late while recognizing the problem etc